Manufacture of filaments in electric incandescent lamps, process and product.



"No. 879,084. PATENTED FEB. 11, 1908.

F. M. P. GAZIN.

MANUFACTURE OF FILAMENTS IN ELECTRIC INGANDESGENT LAMPS, PROCESS AND PRODUCT.

APPLICATION FILED MAY 31. 1904. 2 EHEETS BHEBT 1.

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PATENTED FEB. 11, 1908.

P M. P. GAZIN. MANUFACTURE OF FILAMENTS IN ELECTRIC INGANDBSGENT LAMPS,

PROCESS AND PRODUCT.

APPLICATION FILED MAY 31. 1904.

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UNITED STATES PATENT oE IcE.

FRANCIS M. F. ckzm, OF HOBOKEN, NEW JERSEY.

MANUFACTURE. OF FILAHENTS IN ELECTRIC INCANDESCENT LAMPS, PROCESS AND PRODUCT.

Specification of Letters Patent.

Patented Feb. 1 1, 1908.

Application filed Kay 31' 1904- Serial No. 210.759. I

To all whom it may concern:

Be it known that I, FRANCIS M. F. CAZIN, a citizen of the United States, residing at 1108 Bloomfield street, city of Hoboken, Hudson county, State of New Jersey, have invented an Improvement in Manufacture of Filaments in Electric Incandescent Lamps, Process and Product.

As the records of the U. S. Patent Office show, I had issued to me prior to the date of this application, eight patents, all relating to im )rovements, invented by me in electric lighting, namely: No. 523,460,No. 523,461, N0. 566,285, No. 620,640, NO. 621,291, N0. 621,292, No. 640,366, No. 760,849, and since then of the same kind No. 786,727, No. 770,221, No. 770,223,N0. 770,222, and I have now pending applications for Letters Patent, namely: Nos. 704,218 of Febr. 2, 1899, renewed as No. 102,993 of April 15, 1902; 725,283 of July 27, 1899; 732,399 Of Oct. 2, 1899; 735,439 of 0013.31, 1899; 3,061of Jan. 27, 1900; 138,084 0f Jan. 7, 1903; 145,871 of Mch. 3, 1903; 170,940 of Aug. 27, 1903; 183,270 of Nov. 30, 1903; 198,564 of March 17, 1904; 201,720 of Apr. 5, 1904; 210,193

of May 28, 1904; 210,870 of June 2,19041 220,819 of Aug 15, 1904; 225,347 of Sept.

21. 1004, which relate to improvements in electric incandescent lamps and to methods and tools to be used in their manufacture.

All of the inventions thus by me claimed constitute a successive organic entirety and relate intimately to one another; Itherefore may of necessity refer to and,. cite as substantially a part of this application, from my prior specifications, as hereabove mentioned, in order to eventually more fully and clearly describe my present further and new improvement, as a further organic evolution in my persistent and for long years continued experimental work in the premises ,w1thout these citations in any way constituting new matter, in connection with this specification. The main fundamental purpose of these new improvements has been and is the substitution, be it in part, or entirely or essentially and finally for all organic matter used in the present art as primary or as constituent matter in the lummants of electric incandescent lamps,matter, which as such shows and maintains greater stability under electric current than organic matter. And in such substitution I have introduced for utilization in such luminants the metals of the rutheniumosmium class and the oxids of rare metals.

bility or more scientifically expressed, their high point of fusion. And the cause for my utilization in the making of luminants (filaments, glowers or pencils) for electric lamps of certain rare earths consists in this, that they are peculiarly ada ted to absorb and retain heat, and accumu ate the same to the attaining of high temperatures, and thereby to convert otherwise dark 'heat rays into light-rays,--and to readily emit these lightrays, while kept at high temperature.

It is but proper and opportune, that here I should account for my reasons, technical and otherwise, why I have, as stated, selected as the exclusive methodfor metallizing the fragile, flexible carbon-filaments of the plresent trade, the method of electrolytic eposition of an organic matter or of metals on suitable cores, made in the final form of the glower in the electric incandescent lamp, as one of the electrodes, under normal conditions, where, of sundry materials, the most positive ones, such as metals, are to be deposited, viz. as the cathode in an electroytic lating apparatus. may e stated as follows:

1. While the making of a wire of metals, intended to serve as filaments or glowers in electric incandescent lamps, by the common method of drawing, as known to the art, and as a plicable to malleable metal, resented itsel as the most obvious metho ,actual experimenting showed, that with the utilization of such metals of the platinum-group in part or exclusively, as do not possess malleability, the method of drawing wire was inapplicable.

2. To im art the wire form to these metals, pow erable in their native state, by compressing-their powder in fine tubes by applying high pressure, though successful to a limited degree, had to be considered as impractical on account of the costliness of the manipulation and of the unsatisfactor qualities of the product and of the impossib' ity of arranging the different constituent ma terials in the filament in concentrical layers.

And these reasons 3. The painting of a fillet with paint,

made of these metals, though feasible by.

pro er contrivances, 1n a continuous or rea y manufacturing manner, and althou h the product seemed rimarily to answer t e purpose, had to be iscarded,-because the paint would not adhere to the fillet in the sundry then following necessary manipulations of cutting into proper lengths, bendin into shape, sealing unto the glass-base,'an

least of all when the current was turned on the filament or glower.

.layers and Winds the thus produced compound-fillets into the final lower-form, while drying ofthe'squirted let takes also place in 'vacuo and by passing electrical current through the fillet, even causing a slow and desirable chemical reaction between the core and layer or layers, that fosters adhesion between core and coatings or covers. The ualities indicated by the one word electro ytic when an adjective to the word deposit are as follows:

a. That the deposit is of such minute thinness, that by common methods its thickness can not be measured.

, b. That the deposit covers every exposed part, including those inside of pores as Well as all surface-parts, whether they be smooth or rough, even or uneven.

c. That the deposit is absolutely of equal I thinness everywhere.

- constituted and made, adhere to t e core,

11. That the de osit in all ofits parts is of the same materia and composition, viz. of a uniformity, as nature only and not human art except by the aid of natural action can produce it.

e. That the deposit will, unless im roperly as if consisting of the same material and consistenc throughout. a

f. T at the deposit is of. a kind, that will endure all further manipulations yet required, Without loss of functionally required qualities, such as uniformit cohesion, etc.

g. That its volume (lengtand transverse section) is minutely regulated as well as its conductivity, unless inadequately applied.

I have achieved these im rovements in sundr ways, described or or time being vafiie y alluded to in my prior specifications. y present a phcation is intended to secure rotection or a process and its roduct, 'whic I have invented in the way 0 continuous electrolytic treatment of a core for a prospective luminant which is in the final shape that such luminant is intended to have, it being understood, that these luminants will finally and mainly consist of an organic matter. In executing electric deposition of such an or anic matter, I have invented new and usefu improvements, for'which I intend to obtain protection by patent by this present application.

The essential of such improvements consists, as stated in a certain increased continuity of action, the total of which consists in a series of single mani ulations as follows: I start with drawing or e austing the air from ores or channels that the cathode-core may ave, by the use of an air exhausting apparatus,then I admit certain solutions to the effect of filling these ores and channels with solutions, that contaln the stated metals or rare earths, to the exclusion of the commoner earths, such as lime, alumina, magnesia, 'silica or zirconia,which are unfit for the stated purposes,-and permitting these solutions to penetrate into such air-exhausted pores or channels. This last-mentioned effect is fostered alternately by fully immersing the core in the form intended as final for the prospective luminant, and alternately drying the same. Therefore, when the core has been soaked as described, and is filled with solution, the li uid is Withdrawn and ends and surface of tie core are exposed to the effect of renewed air-exhaustion,whereby the solvent evaporates, the solid matter is retained in the channels and pores of the .core. And this alternate action isrepeated, until not only a complete impre nation is effected but also until the surface 0 the core has been covered, coated or frosted with a film of solid matter such as specified. .That I preferably mention these practicably or nearly infusible metals, and as such considered in the arts and rare earths,-is not intended to indicate that the apparatus and process are not also intended for the' utilization of solutions containing other matter than these so mentioned. I may for instance make use of solutions which contain-other solid matter, with which the prospective glower is to be primarily impregnated or permeated, or with which the prospective glower is to be primarily or finally coated,and of solutions, such as mere alkalies or acids, or of solutions, which contain the infusible metals or the rare earths in other compounds than nitrates, sulfates, oxalates or chlorin com ounds, and as the base of amphidor ha oid-salts, or which contain matter, which though not popularly counted as'of the infusible metals or as of the metal-bases in rare earths, such as titanium, uranium, tungsten and others.

It will be readily understood, why my improved a paratus and process covers the widest fie d in the matter of electrolytes to be used therein, including gaseous electrolytes such action as making of the material to be deposited on the cathode the very body of the anode as for instance when I use an alkaline liquid as electrolyte and a body or bodies, (grains) of iridosmin as the anode. I described the apparatus because in the matter of process it is essential to have it understood, that the various actions,-namely, of air-exhausting,of immersing and impregnating or soak1ng,of drying,orre-immersing,-of electrolytically coating,of subjecting the glower in vacuo to current for the different purposes of causing chemical reactions such as carbureting of metals or such as depositing matter by means of such current,be it on the prospective glower or as conductor, or for producing incandescence, or for the urpose of measuring efficiency, etc. may lie and are performed successive y and alternately in and by the same apparatus in a continuous process and without touching, manipulating or moving or removing the prospective glower. added the statement, that preliminarily or at any stage of the process, even the carbonization of organic matter by means of sulfuric acid, or the carbureting by means of current-produced heat, may be performed in and by the same apparatus and in the same process, consisting in the sundry actions, regardless of consecutive order, but being executed in and with the same a paratus.

It should then be f iilly understood, that the cores or' prospective glowers or filaments,in shape of linear bodies, may ossess porosity and continuous longitu inal channels or possess one of these physical conditions, and which may be of organic or inorganic matter, either ofnatural or artificial origin, viz. silk threads or twigsor wires, or squirted fillets of any substance are placed in the said exhausting and soaking a paratus, when they have been-bent into s a e, which the filament or glower is inten ed to have in the finished lamp. It should also be understood, that the factorymade glassarts for my improvedelectric lamps inclu e,aside of my improved base parts, such as heretofore patented to me',

ulbs, which have necks wide enough to permit the filaments thus primarily bent into their finally intended shape. Thus these filaments may be passed into such bulb or bulbs without bein compressed or squeezed out of shape. By t e use of strong magnify- And to this may yet be ing lasses it has been discovered by me,

that y such squeezing out of shape of the fila ments defects or cracks of very minute dimensions are produced 1n their surface, which, when the filament is under current,

0 en out, and cause quasi-arcs and finally t e parting or snapping of the filament, shortening its life as against the life of filaments, which are properly bent prior) to their main treatment and not bent out of shape again. It is therefore, an important feature of mynew process that the prospective glower or filament, once bent to intended final shape, be it curved or straight, and connected by both its ends to the cathodepole in the apparatus, (compare in application No. 755, 439) or to express it sti l more precisel once being made the recipient for the e eotrolytic deposit the glowers themselves being made the actual cathodes or immersed negative poles in the electrolyte, need not be moved, manipulated, removed or bent out of intended final shape, to finish, complete and perfect it to readiness to be inserted into proper place in the electric lamp, in which it is to serve as the luminant.

In illustration of the process as such I now select out of many others the specific case of impregnating and coating the glower or filament with rare-metal oxids. When repeated and alternate soaking and drying in vacuo has perfected impregnationof the core with any suitable sol1d,1t is normally found necessary to also electrolytically coat the core or to electrolytically complete a artial coatin And when an organic car on-compoun has entered the composition of the prospective filament or core,I preferably carbonize such core prior to entering thesameinto myim rovedap aratus. Again I may be using sulfuric aci carbonize the same when properly placed in my improved apparatus, which serves to this as well as to various other purposes.

In a general way I subject the prospective luminant or core as a first step after it be placed properly in my im roved )lating a paratus to the action 0 an a equate electric current and this is done for the purpose ,of causing right there and then to take place any or all chemical reactions, within such pros ective filament, for which the applied e ectric current may supply the needed energy, to the effect, that in the further prosecution of my improved process no such reaction may interfere in any detrimental way or manner. And such a plying of electric current of adequate tension has the further pur ose of evaporating in vacuo and under the e ect of continued evacuation or air-exhausting all or any volatile matter, that may volatilize at a temperature such as occurring in an incandescent electric lamp, from the prospectiveluminant, and for the purpose of preventing such volatile matter from'later on interfering with the coating, that is to be electrolytlcally deposited on such prospective luminant, or core. I

When a current, causing incandescence is applied within the apparatus on a prospective glower or luminant, into the compositionof which carbon has entered as well as oxids, a reaction and part-decomposition of the oxids is robable, a reaction which leaves part of t e oxids reduced to metal, the result mainly depending on the relative proportions of oxygen and carbon present, thus providing for a means of regulating and controlling the final product thereof, the regulation preferably tending to produce or leave a remainder of oxids and a limited proportion of carburet'ed metal.

In so far as the process and in fact its improved product are not of practicable execution, un ess perfected in an apparatus, which fully provides for every one of the steps combined and rendered possible in roper consecutive selection or order,'-I have adjoined as an essential part of this specification two sheets of drawings with six figures.

Figures 1 and 2 represent vertical sections of my improved apparatus, one section (central) being at right angle to the other. Figs.

and 4 are transverse sections of the same by the indicated line 3-3 in Figs. 1 and 2, the one showing circular-section form of vessels and the other angular section-form of these vessels. Fig. 5 shows the cathode in the apparatus in part and on an enlarged scale; Fig. 6. shows lamp and luminant as by me newly improved, with the large bulbnecks, as exclusively practicable for bent inorganic and brittle luminants.

Similar symbols designate analogous or same parts.

A represents the bell-jar of an apparatus for evacuating or exhausting air, and this bell-jar is preferably made up of two (one topand one bottom) carbon-plates (C and G) and an intermediate hollow glass be it of hexagonal form or be it a hollow glass cylinder or glass tube (a, a), of a comparatively large diameter, the two carbon-plates being ke t in place by means of electrically insu ated bolts, (a, a), and the pipe connection with the exhausting contrivances and pertinent paraphernalia being made by means of the a erture (b) in the bottom plate (C) and the t ereto attached pi e (B) with all its accessories, as known to tlhe art, in racticing evacuation of the electro-lam bu be. The bell-jar contains two vessels D and I) the one mainly inside of the other but electrically insulated from one another, which are resting on the bottom late (C) by means of su ports ((Z, (1). nd both'carbon-plates (G and G) are electrically connected, the top one (G) forming the out-going negative or receiving pole, or cathode, and the bottomcarbon-plate forming the incoming, giving ofi or anode. And electric connection with these plates and poles is made as follows: The top-plate receives the ne ative current, preferably by means of a ro (h) and plug (i), the rod assing by means of a threaded and hermetlcally filled channel, from the carbonlate (G) to the bottom of the inner vessel and operating therein as a valve or lug (i), in a dual function of connecting or hreaking the current and of o ening the com-. munication for a liquid so ution, or viceversa. And in the top-plate (G) there is inserted a ipe-end (g) With a cock for admitting or s utting ofi at will air to the inner space of the bell-jar, (I). Thearran ement t us shown permits the lifting off of t e topcarbon-plate with its accessories,and consequent access to the inner vessel (I) and its removal for the urpose of renewing the charge of prospectlve glowers (L, L, L, e when the rior charge has received full treatment. Al joints must hermetically close, proper means to such end being employed. B- represents the connecting pipe between the bell-jar A and the therewith to be cpnnected apparatus orprovision for evacuation or exhaustion or absorption of air, and with all of the paraphernalia, known to the bulblamp-making trade or art.

C represents the bottom plate of the belljar A, .which plate must be made either of carbon (when used in current connection) or of glass.

D represents the outer ormainly electrolyte-containing vessel of the apparatus, having preferably brackets (d, d) of electrically non-conducting material, fastened to its inside on Which the noses (K, K) of like mate rial and attached to the outside of the inner vessel, rest, to support and hold in place the inner vessel (1). This vessel is preferably made in its vertical part of glass and in its horizontal part of carbon or may be made altogether of carbon.

E, E and E are vessels, which receive the different liquids, such as solutions, hereabove described,acid, volatile carbonaceous or alkaline fluids, etc. or clean water for rinsin purpose, or solutions of metalcom ount s or any other liquid, that may be userv in my continuous and uninterrupted process for preparing glowers of my invention, and as by me often described, in one main operation. But not only are these ves: sels intended to contain the liquids but also to be the means of regenerating the solutions after they have been instrumental inside of my improved apparatus to electrolytic deposition, by covering their bottom with soluble matter of adequate selection. By rep,- resenting these vessels E, E E i etc. as mainly and primarily intended to contain liquid matter, I do in no wise Waive my intention or privilege to select one or another thereof in the form of'a closed vessel, in which gaseous matter is produced (such as the tetra-oxid of osmium) and to be used, as the liquids are, as an electrolyte in the plating vessel D. The vessels E etc. may stand in part or all on a level with the vessel 1, in place of below.

F represents the pipe-connection, such as specified of the vesselD and passing hermetically through the'platform C.

G represents the top-part of the bell-jar, viz. the cover, which is the counterpart of the platform 0 and therewith and with the intermediate hollow glass-cylinder forms the belljar of the exhausting apparatus and provides for the air-valve g, and for the hermetical passage of the handle it and the stopper '0 that acts in an aperture through the ottom of the vessel.

I represents a vessel suspended in vessel D on brackets 11, d by rejections 'i, t.

K re resents the er orated bottom of the vessel which pe orated bottom is shown in view in Fig. 3, and which as such is specifically described herebelow. That I have shown vertical perforations, does notsignify the intention to waive the making of inclined (non-vertical) perforations' The diameter of these perforations will be determined by the preference for either inserting the ends of the filaments directly or by means of a glass-tube on which they are mounted by a hermetical joint. In either case the insertion is preferably made by means of a bees-wax-coating causing the insertion to be hermetical.

L represents the prospective glowers or luminants in the form of bendings and loops, that they are to have in the finished lamp. That there is a limited number of them does not signify, that the dimensions of the aparatus may not be increased to place a l ar er number thereof simultaneously in the sair l plate K. It has been found to be, the preferable practice to insert these filaments 1n the plate K,--not on a perfectly vertical up-and-down line in themselves, such as they are shown to occupy in Fig. 1.,but on a somewhat inclined up-and-down line, otherwise preserving both the parallelity between them as well as the right angle between the line, on which the series stands, and the plane, in which the filament is bent, because the ascending liquids affect them then in a uniform manner, causing them to maintain uniform distances from one another. It may be'observed, that the joint between the heating and non-heating part of the conductive element (prospective) is in a position, where any eventual deposit would cover the terminals also. Such being the intention, the cupshaped terminals bei these glowers, are, w en present, made -to slip back on the inleading wires temporarily, and are slipped to cover the terminals on y preferably used with I have stated hereabove, that the apparatus, as shown in the drawings, and as thus described serves two essentially different functions, though both pertain to the manufeature of improved glowers of the s ecified kind, and though both form toget er the combination of performances, that constitute an improved process of manufacture. The

one function is that of cellulose-carbonization by means of sulfuric acid,and the other is that of impregnating and coating with solid material by means of solutions. And to this should be further specified as functional performance, the subjecting to incandescing current and consequent chemical reactions and vaporization of volatile constituents in the prospective lowers. The alternation between the bodies eing in a vacuum and being immersed in the li uid', that is adapted to the function, wit out being handled, manipulated or disturbed in its shape during the operation,-which achieves the pur ose as set, and which constitutes the chic merit of the rocess, and the superior quality of the there y produced product.

In explaining the modus 0 ercndi, I now refer to ,the making of the fi ament in successively using the different liquids or gases or either, namely in case carbonization is to be primarily performed in a first operation sulfuric acid and in subsequent operations salt-solutions of the stated rare-earths and of infusible metals or gaseous compounds thereof or acids or alkaline liquids, or volatile carbonaceous liquids.

In a general way it is immaterial in o erating under any improved method an with my improved apparatus,whether the solutions to be used in the same are made to rise into the same either by hydraulic equilibrium when the vessels E, E, E etc. are placed at an elevation to roduce this effect,'or whether by means 0 rarefied air or reduced atmospherlc pressure inside of the bell-jar A the liquids are alternately drawn (sucked) into the plating vessel D. To illustrate the operation it is assumed that the lat- 'the glass tube F leading to the be l-j ar A and vessel D. The liquids are mainly intended to ascend to very near the bottom of the vessel when the exhausting a paratus is set to operate on the be1l-jar A uy the tube B (the cock in the air-valve 9 being shut,) the acid will slowly rise in the tube F and into the vessel D overflowing only into the vessel I, when the een removed or raised into the inner vessel I. If then the cock f is closed,.

and the air-exhausting is Continued (proper precaution being taken for condensing the escaping fumes, outside of the apparatus proper,carboniz'ation of any cellulose-matter present in the fillets to be within the prospective glower, will take place. If then the exhausting actionis stopped (cock in the glasstube B being shut),and the air-admissionvalve g is opened,the sulfuric acid will recede back into the vessel F. Theanalo ous action is performed in relation to ves'se F, which may contain clean water, by which insuch action sur lus of acid is removed and the vessel D rinse out. When all connections with the vessels, E, E, E etc. containing li uids are closed by corks and when a suitab e vacuum in the bell-j ar hasbeen accomplished by air-exhaustion thro ughthe tube B then any channels or pores in the prospective glowers willbe air-evacuated.

My experience has been, that there is, in usingmy improved process, no necessity for carrying the 'carbomzation out to full perfection, or to the effect that the core art of the fillet remains uncarbonized, and t at no detrimentary effect thereof will be experienced,because carbonization may subsequently be completed by the effect of an in candescing electric current. Before proceeding to that, which is not optional, as the just described carbonizing is, and which may be included in my process or be left out, for independent outside action,I should state the influence which has been 0 erative on the shaping of my drawings by t e assumption that the carbonizing function also be performed in my improved apparatus. The ottom-plate C was mentioned as made entirely or in part of either glass or carbon, as well as the two vessels D and I of the electro lytic apparatus proper. They may, with the step of carbonizing performed outside, as independent action consist of other functionally e uivalent material such as japanned or varnieliedmetal, for the assi ned functions. The prospective glowers, aments or pencils may be inserted directly into the bottom-plate K of the inner vessel I. But it is my preferable practice to insert them inter mediately by means of mounting them'on a tubular or bottleshaped glass body, such as shown in my prior patents,or as shown in the adjoining drawing Fig. 5, .which glass bodies hermetically hold the leading-inwires 8, 8 and these holding at one end the glowers L and maldng electrical connection with the other end. Selecting this modifi cation of holding the glowers in the bottomplate of the vessel I, the perforations are preferably made to cause the filaments to stand in series and on an incline between 10 and 15 from the vertical perforations, large enough to receive the open-end of the glassholders D ,-are provided in the said bottom. (Shown in Fig. 3.) It is obvious that the leading-in-wires must be inter-connected to the ne ative pole of the apparatus whenever electro ytic action and deposition therein is intended. The metallic or metal-com-' pound deposit is intended referably to reach over and above or to inc ude the immersed terminals and immersed parts of the leading in-wires.

In the second last paragraph of the second page of this specification, I have described the further 'lhOdflLS operandi or that, which is the essential of my new combination-process and conditional to the improved product in electric glowers manufactured by such process. It therefore remains only to speak of the electrical conditions to the apparatus and process.

It is obvious, that the apparatus as and as an entirety must be insulated from the earth. If the pipes f, f and f are as indicated, made of glass, the vessels F, F and F might not be so insulated, though I find the apparatus to do more accurate work,

self-regu ating,requires in fact guidance by one versed in theelectric and in special in the electroplating art,it is labor-saving and economical to a high. degree, because the one apparatus performs many sundry functions which are now performed only by much handling of the tender glowers-and by removing the prospective glowers from apparatus to apparatus. By such handling and transporting the perfect preservation of these delicate filaments, pencils or glowers is materially jeopardized. Aside of this my improved method and apparatus utilizes air evacuation for further new and useful purposes.

I intend to limit in this case my claims to electro-plating a core in the final shape of the prospective glower, though I am aware of the practical possibility of roducing otherwise equivalent glowers by tile process of winding the core for the prospective glowers, in the length of many, over a air of mandrils, which form the negative po e in the plating apparatus and then cuttin the plated glowers into proper lengths and iend such .when these vessels also are in'sulatedfrom the same into shape. But I introduced this limitation in this case, because I believe to cover this process without such limitation by other applications for Letters Patent.

That which I desire to secure by Letters Patent is as follows:

1. A, lower-filament in an electric incandescent amp, which glower-filament consists of a metallized carbon-fillet in the form, selected for the glower in operation,the metallization consisting in an electrolytic deposit of different metals, of which those in contact primarily with the carbon are partly inter-impregnated with the carbon,and those on the surface coated with'oxid, all of which metals have a high point of fusion, the inner-ones having more and the outer-ones less affinity for oxygen.

2. A lower-filament in an electric incandescent amlp, which glower-filament, including termina s, consist of a carbon-fillet primaril bent longitudinally in the shape of the comp eted glower and its metallization by means of electrolytic metal-alloy-deposits of different classes of metal, of which the deposit in immediate contact with the carbonfillet consists of metals of the rutheniumosmium class and isin part. inter-imprege nated with the carbon, and of which the outer deposit consists of metal of the rare class and is coated on the exposed surface with oxid.

3. A glower-filament in an electric incandescent lamp, which glower-filament consists of a metallized carbon-fillet,the metallization of which fillet consists of electrolytic alloy-deposits in concentrical layers, the inner layer consisting of metals of the ruthenium-osmium class and being on its contact with the carbon inter-impregnated therewith, and the outer layer of which consists of rare metals, the surface of whichis covered with oxids.

4. A metallized lower-filament in an electric incandescent amp, which consists of a carbon-fillet, primarily in the final longitudinally bent shape of the glower filament in the lam and of its metallization, which primarily consists of electrolytic alloy-deposits in concentrical layers, the inner layer-com sisting primarily of metals of. the ruthenium-osmium class and being on its contact with the carbon inter-impregnated therewith, and the outer layer of which consists lamp in operation,and-of its metallization,

which consists primarilyof electrolytic alloydeposits in c-oncentrical layers, the inner layer of which consists of metals of high point of fusion and of affinity for oxygen of the latinum group of metals, which metals on their contact with the carbon of the fillet have become inter-im regnated therewith, and the outer layerof which consists of rare metals-end is coated on its exposed surface with oxids.

6. The rocess of manufacturing a glowerfilament or an electric incandescent lamp, which process consists in metallizing a carbon-fillet in the form, selected for the same to have when in operation, the metallization consisting in electrolytically depositing on the carbon-fillet different metals of high point'of fusion, of which those coming into contact primarily with the carbon are being partly impregnated with carbon, and those on the surface are being coated with oxid, the. said metal bein deposited in such order, that the inner-onesiave more and the outerones less affinity for oxygen. r

7. The rocess of manufacturing a glowerfilament or an electric incandescent lamp, which process cbnsists in metallizing a carbon-filament including its joints or terminals with the inlea'ding wires and bent longitudinally in the shape of the completed filamentglower by means of electrolytically depositmg in concentrical layers unto such filamentglower of carbon-metal-alloys, of which the inner deposit consists of alloys of the metals 95 of the ruthenium-osmium class and the outer-one of metals of the rare-metal class,

the latter being coated on its exposed surface with their oxids and the innermost being partly impregnated by the carbon of the 10C fillet.

FRANCIS M. F. CAZIN.

Witnesses:

MINNA E. 'CAZIN,- C. T. Hnssnn. 

